Manufacture of electric conductors



(No Model.)

E. G. AGHESON 8v B. F. ANDERSON.

MANUPAGTURB 0F ELECTRIC GONDUGTORS. No. 380,158. Patented Mar. 27, 1888.

my wat@ u' @wozu-mijn UNITED STATES -PATENT OFFICE.

EDWARD G. ACHESON AND BENJAMIN F. ANDERSON, OF PITTSBURG, PENNSYLVANIA.

MANUFACTURE OF ELECTRIC CONDUCTORS.

SPECIFICATION forming part of Letters Patent No. 380,158I dated March27, 1888.

Application filed July1 2l, 1887. Serial No. 244,911. (No model.)

To @ZZ wwm it may concern:

Be it known that we, EDWARD G. AcHEsoN and BENJAMIN F. ANDERSON,residing at Pittsburg, Allegheny county, Pennsylvania,- have inventedcertain new and useful Improvements in the Manufacture of ElectricConductors, of which the following is a specification.

Our invention relates to the manufacture of electrical conductors; andit has for its object to produce a cheap and effective conductor that isnot subject to the inductive disturbances due to neighboring electriccurrents, or that may be used as a return or complete metallic circuit,and one that at the same time will be iieXible and capable of being bentand twisted without danger of injury.

To these ends our invention consists in the method of manufacturingelectrical conductors, substantially as hereinafter set forth.

Prior to our invention a conductor has been made consisting of aprimary-line wire covered with some insulating material over which hasbeen applied a shield or covering of metal, and this metal has beenapplied to the insulated conductor by electrolysis. The metal shield orcovering as thus applied, while furnishing a perfect conductor orshield, is subject to some mechanical objections, principal among whichis the lack of flexibility and the danger of rupturing the covering orshield when the conductor is bent or twisted, as is often desirable inusing the same. If the bend in such a conductor is too great, thecovering or shield is liable to crack on the outside of the bend, andsuch cracks generally being transversely to the conductor are liable tointerfere with the conducting qualities of the covering, as well as tointerfere with the perfect insulation of the primary conductor. 'Inorder to overcome this objection, we make a conductor with a covering orshield having spiral grooves extending partially or wholly through thesame, so as to allow the conductor being easily bent without danger ofdestroying the continuity of the conducting shield or covering orinjuring the insulation; and our invention relates to the manner ofproducing such spirally-grooved covering by electrolysis.

While Various means may be used in carrying out our invention, we haveillustrated in the accompanying drawings one form of appa ratus that wehave found cheap and effective,

in Figure 1, and Fig. 2 is a detail of a modification.

The primary conductor A, after being coated in any desired manner withany proper insulating material, B, but preferably some material having acomparatively high meltingpoint, as asphaltum, is passed through a box,C, containing powdered graphite, or equivalent, that will adhere to theinsulating covering and furnish a good surface for the electricaldeposition of metal. The conductor as thus prepared is subjected to theaction of an electrolytic bath, D, in the usual manner, and we haveshown a comparatively long bath,through which the prepared conductorpasses continuously, receiving the deposit of metal as it moves throughthe electrolyte. This operation would cover the insulated conductor witha uniform coating of deposited metal, and in order to form spiral orother grooves in the covering it is only necessary to stop out thedeposition partially or wholly, and this may be done in various ways.

We have shown at E a device carrying a spool of thread, which isrevolved around the insulated conductor as it moves along through thedevice, and which thereby winds a thread or cord spirally around theconductor. This thread or cord should be of some non-conducting materialthat will act as a resist to the deposition of the metal, and while anyordinary cotton or other thread may be used, we prefer to use a waxed oroiled thread or cord. This thread or cord may be applied to theinsulated conductor before it passes into the graphitebox, and then beremoved, as it thereby prevents the coating of the insulating materialwith the plumbago, and therefore the metal will not be deposited fromthe bath on the uncoated portions; but we prefer to apply the cord afterthe plumbago coating, as shown in the drawings.

The inclination and size of the spiral groove may be readily determinedby the relative rates of rotation of the spool and travel of theinsulated conductor and by the size of the thread or cord. When the cordis wound tightly upon the Ainsulated conductor, no metal IOO will bedeposited upon the portions covered by the cord; but if the cord isloosely wound over the graphite very little metal may be depositedaround and under the inner side ofthe spiral, and the grooves therebyextend only partially through the deposited coating.

Instead of using a thread or cord, the device E may be made to apply aspiral line of nonconducting material on the insulated conductor thatwill act as a resist and prevent the deposition of the metal from thebath; and in Fig. 2 is shown onesform of device for applying the resist,consisting of a brush holding the liquid resist material carried aroundthe wire as it passes through the axis of the brush-carrier.

The conductor, after receiving its metal covering, may be passed throughanother vat, F, and receive a coat of paint or japan, and it may then bepolished or otherwise treated to nish the conductor, as desired. Theconductor thus made has a continuous covering with spiral grooves orrecesses that permit of its being bent Without danger.

It will be understood that we do not limit ourselves to the mechanismshown, nor to the precise mode of procedure set forth, as it is evidentthat it can be varied by those skilled in the art Without departing fromthe principle of our invention.

l. In the manufacture of electrical conductors, the method,substantially as herein set forth, of forming a covering with spiralgrooves therein, which consists in applying a resist of non-conductingmaterial upon the conductor 35 and subjecting the conductor to theaction of an electrolytic bath.

2. In the manufacture of electrical conduct ors, the method,substantially as herein set forth, of forminga covering with spiralgrooves 4o therein, consisting in winding a thread spirally around theinsulated conductor and electrolytically depositing a covering' on theconductor.

3. In the manufacture of electrical conduct- 45 ors, the method,substantially as herein set forth, of forming a covering with spiralgrooves therein, consisting in applying` a spiral of waxed thread to theconductor and subjecting it to an electrolytic bath.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing witnesses.

EDWARD G. AGHESON. BENJAMIN F. ANDERSON. Vitnesses:

M. F. CAssrnY, WILLIAM H. DrLLs.

